Tire sensors are used, in particular, for measuring internal tire pressure (tire pressure monitoring system, TPMS), as well as the temperature or accelerations which occur inside of the tire. In this connection, a sensor module typically includes a circuit substrate, at least one sensor component, and an antenna via which data are transmitted to a transceiver on the vehicle. Two types of conventional systems supply power. In one system, the energy is supplied by a battery or a galvanic cell, and, in the other, by electromagnetic radiation or incoupling.
An autonomous, battery-based energy supply raises environmental concerns, particularly because of high disposal costs and the outlay entailed in separation processes during disassembly. Tire sensor modules of this kind are typically mounted on the tire rim since the galvanic cells used as batteries must be disposed of separately from the rubber tire material and since they do not tolerate the temperatures that occur in the tire during vulcanization. In addition, the service life is limited by the capacity of the battery which often is not replaceable; since the sensor module is limited in size, the batteries should not be dimensioned to be too large.
When current is supplied by electromagnetic radiation, respectively, incoupling, in principle, a passive transponder is formed; however, the signal that can thereby be read out is weak. In addition, a high-intensity query signal is needed.